REGTEST: Add option to use HTX prefixed by the macro 'no-htx'

So some tests have been removed.
diff --git a/reg-tests/lua/b00003.vtc b/reg-tests/lua/b00003.vtc
index d785f77..89ab499 100644
--- a/reg-tests/lua/b00003.vtc
+++ b/reg-tests/lua/b00003.vtc
@@ -36,6 +36,7 @@
         log ${Slog_addr}:${Slog_port} local0 debug err
         log-format Ta=%Ta\ Tc=%Tc\ Td=%Td\ Th=%Th\ Ti=%Ti\ Tq=%Tq\ TR=%TR\ Tr=%Tr\ Tt=%Tt\ Tw=%Tw
         mode http
+        ${no-htx} option http-use-htx
         bind "fd@${frt}"
         http-request use-service lua.donothing
 } -start